Fri, 30 Jul 2010
Companies that sell direct-to-consumer (DTC) gene-testing kits have had a tumultuous time in the past ten days. On 19 and 20 July, at a hearing held by the US Food and Drug Administration (FDA), regulators heard comments from stakeholders about how the government might best oversee the validity and accuracy of such tests and other in vitro diagnostics.
Later in the same week, at a congressional hearing, the US Government Accountability Office presented results from a damning year-long investigation into the DTC gene-testing industry that characterized some of the tests as "misleading" and "of no practical use," and the marketing surrounding them as deceptive and fraudulent.
Many in the field of genomics and personalized medicine--in both academia and industry--concede that regulation is necessary. ... The fear, however, is that government backlash against questions over the tests' validity and inconsistent results from different companies will lead to an overly strict regulatory framework that will crush scientific innovation.
Mon, 19 Jul 2010
One woman panicked when the genetic test she had ordered over the Internet concluded that her son was carrying a life-threatening disorder and, even more disturbing, that he was not--genetically--her son. Another, who always thought she was white, was flabbergasted to find her genes were mostly of African origin. A third woman's result was still more stunning: She was a man, it said.
"I thought, 'Oh my God. Am I really a man?' " said Denise Weinrich, 48, of St. Peters, Mo. "I thought, 'What's the matter with me? I'm not who I thought I was. How am I going to tell my children?' DNA doesn't lie."
DNA does not lie, but its truth is often elusive. Weinrich was one of 87 people who received incorrect results last month because of a laboratory mix-up involving customers of 23andMe, a testing company backed in part by Google. The Mountain View, Calif., testing company says it regrets the incident and noted that it spotted the mistakes quickly, notified the clients and has taken steps to prevent future errors.
Mon, 12 Jul 2010
Every Wednesday at 3:15 p.m., a few dozen Stanford University medical students turn their backs on the sun, gather in a high-tech classroom and flip open their laptops.
The summer class they're taking is a foray into the future of medicine. The course title, Genetics-210, Genomics and Personalized Medicine, betrays little about how personal the journey will be. The students will study their own DNA and unlock the mysteries of their ancestry, medical destiny and longevity.
"The students will learn troubling things," says Stanford geneticist Stuart Kim, the class's faculty sponsor. "You will learn that you have a predisposition for lots of different diseases. Some may learn that their ancestors aren't who they thought they were, that their father isn't their real father."
Thu, 1 Jul 2010
Geneticist Mayana Zatz has been working for nearly two decades with patients who have inherited disorders. When it comes to genetic testing, Zatz advocates caution. Tests for some inherited disorders have helped people decide whether or not to have children. But in most cases, Zatz says genetic testing raises complex psychological and ethical issues.
Should children be tested for late-onset disorders such as Huntington's disease and cerebellar ataxia? Doing so could lead to a life of dread, as they wait for a disease for which there is no cure. Interpreting the results from a genetic test can be difficult, especially for complex diseases such as cancer or Alzheimer's which are triggered by multiple factors, not just genetics.
Zatz, who directs the Human Genome Research Center at the University of Sao Paolo, is our guest in the Science Forum. She is taking comments and questions through July 13th.
Thu, 13 May 2010
Walgreens late Wednesday reversed a decision to carry genetic test kits in its stores after the U.S. Food and Drug Administration began an investigation of the supplier and product.
Deerfield-based Walgreen Co. had planned to begin stocking thousands of stores nationwide with the Pathway Genomic home test kit on Friday. Walgreens' decision was announced after the FDA released an enforcement letter sent to San Diego-based Pathway Genomics, giving it 15 days to respond to the agency's request for information regarding its controversial genetic home test kit.
"In light of the FDA contacting Pathway Genomics about its genetic test kit and anticipated ongoing discussions between the two parties, we've elected not to move forward with offering the Pathway product to our customers until we have further clarity on this matter," said Jim Cohn, a Walgreens spokesman.
Wed, 12 May 2010
Beginning Friday, shoppers in search of toothpaste, deodorant and laxatives at more than 6,000 drugstores across the nation will be able to pick up something new: a test to scan their genes for a propensity for Alzheimer's disease, breast cancer, diabetes and other ailments.
The test also claims to offer a window into the chances of becoming obese, developing psoriasis and going blind. For those thinking of starting a family, it could alert them to their risk of having a baby with cystic fibrosis, Tay-Sachs and other genetic disorders. The test also promises users insights into how caffeine, cholesterol-lowering drugs and blood thinners might affect them.
The over-the-counter test marks the first foray of personalized genomic medicine into the corner drugstore. The move is being welcomed by those who hope that deciphering the genetic code will launch a new era in biomedical science. But it's being feared by those who worry it will open a Pandora's box of confusion, privacy violations, genetic discrimination and other issues.
Tue, 11 May 2010
What makes two individuals different? Biologists now know that the genome sequence holds only a small part of the answer, and that key elements of development and disease are controlled by the epigenome--a set of chemical modifications, not encoded in DNA, that orchestrate how and when genes are expressed.
But whereas faster, cheaper and more accurate sequencing technologies have developed rapidly, techniques to map the epigenome have lagged behind.
Sequencing company Pacific Biosciences, based in Menlo Park, California, has now developed an integrated system that simultaneously reads a genome sequence and detects an important epigenetic marker called DNA methylation. ... DNA methylation, which reduces gene expression, is linked to key developmental events, as well as many types of cancer.
Wed, 5 May 2010
A Stanford bioengineer has become the first scientist in the world to decode his own DNA with a machine he invented, allowing him to peer into his genetic blueprint to see his risk for disease—and expanding the frontier of medicine.
"I was curious about what was written in me," said Stephen R. Quake, 41, who has devoted the past decade to building the technologies behind his Heliscope Single Molecule Sequencer. "I'm following the great tradition of scientists who experiment on themselves."
A decade ago, sequencing of the first-ever whole genome by the federal government took many years and cost $400 million to $500 million. Quake's machine, the size of a freezer, sequenced his human genome in only four weeks, for $50,000. The procedure is expected to cost $10,000 by the end of this year.
Wed, 7 Apr 2010
One hour of moderate to vigorous exercise a day can help teens beat the effects of a common obesity-related gene with the nickname "fatso," according to a new European study. The message for adolescents is to get moving, said lead author Jonatan Ruiz of the Karolinska Institute in Sweden.
"Be active in your way," Ruiz said. "Activities such as playing sports are just fine and enough." The study, released Monday, appears in the April edition of Archives of Pediatrics and Adolescent Medicine.
The research supports U.S. guidelines that tell children and teenagers to get an hour or more of physical activity daily, most of it aerobic activity such as running, jumping rope, swimming, dancing and bicycling. Scientists are finding evidence that both lifestyle and genes cause obesity and they're just learning how much diet and exercise can offset the inherited risk.
Thu, 11 Mar 2010
Two research teams have independently decoded the entire genome of patients to find the exact genetic cause of their diseases. The approach may offer a new start in the so far disappointing effort to identify the genetic roots of major killers like heart disease, diabetes and Alzheimer's.
In the decade since the first full genetic code of a human was sequenced for some $500 million, less than a dozen genomes had been decoded, all of healthy people. Geneticists said the new research showed it was now possible to sequence the entire genome of a patient at reasonable cost and with sufficient accuracy to be of practical use to medical researchers. One subject's genome cost just $50,000 to decode.
"We are finally about to turn the corner, and I suspect that in the next few years human genetics will finally begin to systematically deliver clinically meaningful findings," said David B. Goldstein, a Duke University geneticist who has criticized the current approach to identifying genetic causes of common diseases.
Thu, 18 Feb 2010
Some of mankind's most devastating inherited diseases appear to be declining, and a few have nearly disappeared, because more people are using genetic testing to decide whether to have children.
Births of babies with cystic fibrosis, Tay-Sachs and other less familiar disorders seem to have dropped since testing came into wider use, The Associated Press found from interviews with numerous geneticists and other experts and a review of the limited research available.
Many of these diseases are little known and few statistics are kept. But their effects—ranging from blood disorders to muscle decline—can be disabling and often fatal during childhood. Now, more women are being tested as part of routine prenatal care, and many end pregnancies when diseases are found. One study in California found that prenatal screening reduced by half the number of babies born with the severest form of cystic fibrosis because many parents chose abortion.
Thu, 18 Feb 2010
Scientists have analysed the genomes of five southern Africans, including Archbishop Desmond Tutu, to study their genetic diversity and health. The research, published in the journal Nature, compared genes of the Archbishop with San people.
"I am excited by the results," Archbishop Tutu told BBC News. "Without these tests, I would not have known my bloodline... I am related to the San people, the first people to inhabit Southern Africa," he explained.
... The team of researchers from Africa, America and Australia hope that the study will help redress the geographic imbalance in disease susceptibility studies based on genetics. Southern Africans have often been poorly represented in drug trials and it will now be possible to include them in genome based studies on disease.
Thu, 11 Feb 2010
The genome of a man who lived on the western coast of Greenland some 4,000 years ago has been decoded, thanks to the surprisingly good preservation of DNA in a swatch of his hair so thick it was originally thought to be from a bear.
This is the first time the whole genome of an ancient human has been analyzed, and it joins the list of just eight whole genomes of living people that been have been decoded so far. It also sheds new light on the settlement of North America by showing there was a hitherto unsuspected migration of people across the continent, from Siberia to Greenland, some 5,500 years ago.
The Greenlander belonged to a Paleo-Eskimo culture called the Saqqaq by archaeologists. On the basis of his genome, the Saqqaq man's closest living relatives are the Chukchis, people who live at the easternmost tip of Siberia.
Wed, 27 Jan 2010
Last fall, Sgt. Timothy Gall, an Army medic stationed at Fort Belvoir, sought clues to the multiple sclerosis and heart disease that ran in his family by looking into his DNA. All it took was some spit and about a thousand bucks.
He didn't go to a doctor. Instead, Gall, 30, joined the growing number of consumers ordering scans of their DNA directly from private companies. A handful of companies such as 23andMe, Navigenics and Decode Genetics offer customers a personal peek at their genetic code, finding variations linked to certain traits, diseases and drug sensitivities—a process known as genotyping. As the cost of genetic scanning has dropped and the pace of genetic discovery quickened, these companies began springing up about three years ago. Now, as they're attracting more and more customers, they're also drawing more scrutiny.
Once Gall decided to try it, he persuaded his father to be genotyped, too. As a quality check, both men mailed saliva samples to two testing firms: 23andMe, based in California's Silicon Valley, and Decode, of Reykjavik, Iceland. "I figured I'd only pay attention to the results where both companies agreed," Gall said.
Mon, 25 Jan 2010
New York has become the latest of a handful of jurisdictions to permit a controversial use of DNA evidence that gives law enforcement authorities a sophisticated means to track down criminals.
Under a state rule approved in December, DNA found at a crime scene that does not exactly match that of someone in the state's DNA database can still be used to pursue suspects if the DNA closely resembles that of someone on file. Since family members share genetic traits, a partial DNA match allows investigators to narrow searches to relatives of people whose DNA is already in the state database, forensic experts say.
Thu, 14 Jan 2010
Hope of a new treatment for Alzheimer's was raised after scientists discovered a 'longevity gene' that protects against the disease. Researchers found that people with two copies of this gene had a 70 per cent reduced risk of developing the disease compared to those without it.
Scientists at the Albert Einstein College of Medicine of Yeshiva University in New York city, America, found that the gene helped to slow age related decline in brain function.
The findings, published in the Journal of the American Medical Association, could lead to new treatments for the condition. Drugs that act in a similar way are now in development.
Mon, 16 Nov 2009
By modifying a single gene, scientists have made Hobbie-J the smartest rat in the world, a new study says.
A similar gene tweak might boost human brainpower too, but scientists warn that there is such a thing as being too smart for your own good.
For years scientifically smartened rats have skittered through movies and books such as Flowers for Algernon and The Secret of NIMH. But Hobbie-J is anything but fiction. The lab rat can remember objects three times longer than her smartest kin, the study says. Thanks largely to this memory boost, she's also much better at solving complex tasks, such as traveling through mazes using only partial clues to find rewards—a key method for measuring rat intelligence.
Mon, 16 Nov 2009
A landmark antidiscrimination law—the Genetic Information Nondiscrimination Act—will take effect in the nation's workplaces next weekend, prohibiting employers from requesting genetic testing or considering someone's genetic background in hiring, firing or promotions.
The act also prohibits health insurers and group plans from requiring such testing or using genetic information—like a family history of heart disease—to deny coverage or set premiums or deductibles.
"It doesn't matter who's asking for genetic information, if it's the employer or the insurer, the point is you can't ask for it," said John C. Stivarius Jr., a trial lawyer based in Atlanta who advises businesses about the new law.
Tue, 10 Nov 2009
The genome of a domestic horse has been successfully sequenced by an international team of researchers. The work, published in the journal Science, may shed light on how horses were domesticated.
It also reveals similarities between the horse and other placental mammals, such as bovids—the hoofed group including goats, bison and cattle.
The authors also found horses share much of their DNA with humans, which could have implications for medicine. Horses suffer from more than 90 hereditary diseases that show similarities to those in humans.
Fri, 16 Oct 2009
Almost a decade after the human genome project lay bare the building blocks of life, scientists have figured out how they work together to create a living person. The genome project identified about 25,000 genes that are needed to make a healthy human being, but said nothing about how they combine to produce everything from hearts and minds to legs and livers.
Now researchers in California have published what is effectively the first manual to show how genes are orchestrated inside cells - a milestone that promises to revolutionise scientists' understanding of human development and how it can sometimes go wrong.
Mon, 12 Oct 2009
Scientists have worked out the 3D structure of the human genome. Their findings, published in Science magazine, reveal how long strands of DNA code are folded and tightly packed into the nucleus of a human cell.
Unfolded, the cell's genome—those strands of DNA code—would be approximately 2m in length. The team showed how this is organised into a tight ball to fit inside a nucleus, which is about one hundredth of a millimetre in diameter.
The US-based research team developed improved DNA sequencing and computational methods to build a model of the genome.
Thu, 8 Oct 2009
Scientists have generated the most comprehensive map of the structural variation that exists among normal, healthy humans, according to a study published online today in Nature. Understanding normal variation between individuals is critical to identifying abnormal changes that may contribute to a wide variety of heritable diseases.
"I think it's considered to be a landmark paper," said geneticist Frank Speleman of the Center for Medical Genetics Ghent at Ghent University Hospital in Belgium, who was not involved in the work. "It's quite important in the complete context of genome wide association studies and genetic predisposition."
Using microarrays that contained more than 42 million probes, genome scientist Stephen Scherer of The Hospital for Sick Children in Toronto and the University of Toronto and his colleagues searched the genome of 40 healthy individuals for copy number variants (CNVs)—areas of the genome that come in varying quantities as a result of deletions, insertions, or duplications. The researchers identified 11,700 CNVs 443 base pairs or greater in size, with an average of approximately 1,000 CNVs differing between any two individuals.
Wed, 30 Sep 2009
Scientists are greeting with surprise and dismay a project to use DNA and isotope analysis of tissue from asylum seekers to evaluate their nationality and help decide who can enter the United Kingdom.
"Horrifying," "naive," and "flawed" are among the adjectives geneticists and isotope specialists have used to describe the "Human Provenance pilot project," launched quietly in mid-September by the U.K. Border Agency. Their consensus: The project is not scientifically valid—or even sensible.
"My first reaction is this is wildly premature, even ignoring the moral and ethical aspects," says Alec Jeffreys of the University of Leicester, who pioneered human DNA fingerprinting.
Thu, 17 Sep 2009
Ten years ago this month the promise of using normal genes to cure hereditary defects crashed and burned, as Jesse Gelsinger, an 18-year-old from Tucson, Ariz., succumbed to multiorgan failure during a gene therapy trial at the University of Pennsylvania. Today the boardroom of the Translational Research Lab at the university is filled with artifacts reminiscent of the trial.
Books such as Building Public Trust and Biosafety in the Laboratory sit on the shelves, and ... scribbled on the whiteboard [are] abbreviations representing some of the very immune factors that fatally spiraled out of control in Gelsinger's body.
These allusions to the past aren't surprising considering how drastically the clinical trial changed gene therapy and, in particular, the career of James M. Wilson, the medical geneticist who headed Penn's Institute for Human Gene Therapy, where the test took place.
Tue, 15 Sep 2009
A master gene that helps mobilise the immune system to fight disease has been discovered by UK scientists. It causes stem cells in the blood to become disease-fighting "Natural Killer" (NK) immune cells. It is hoped the discovery will lead to new ways to boost the body's production of these frontline cells—potentially creating a new way to kill cancer.
The Nature Immunology study may also help development of new treatments for type 1 diabetes and multiple sclerosis. These conditions are caused by a malfunctioning immune system turning against the body's own tissues, and it is suspected that faulty NK cells play a key role in this process.
The researchers, from Imperial College London, University College London and the Medical Research Council's National Institute for Medical Research have created mice that lack the key gene—E4bp4.
Two European research teams have identified three genes that affect a person's risk of developing Alzheimer's disease, the most common cause of dementia in the elderly.
The new genes appear to have at least as big a role as four others discovered in the last 15 years that are known to play a role in Alzheimer's.
...The new findings, reported Sunday in the journal Nature Genetics, will have no immediate consequence in either diagnosis or treatment of the disease. However, they will help illuminate a process that goes on for years or even decades before memory loss, the cardinal symptom of the disease, becomes apparent.
Thu, 27 Aug 2009
NEW YORK (Associated Press)—An experimental procedure that someday may enable women to avoid passing certain genetic diseases on to their children has gained an early success, with the birth of four healthy monkeys, scientists report.
The technique still faces safety questions and perhaps ethical hurdles, but an expert called the work exciting. The experiment, which involved transferring DNA between eggs from rhesus macaques, was described Wednesday on the Web site of the journal Nature by researchers from the Oregon Health and Science University.
Someday, the technique may be used against diseases caused by inherited defects in the "power plants" of cells, called mitochondria. These conditions are uncommon and unfamiliar to most people, such as Leber hereditary optic neuropathy. Roughly one person in every 4,000 or 5,000 either has one of these mitochondrial diseases or is at risk for one.
Wed, 19 Aug 2009
Sean Delshad, 19, probably could have found more enjoyable things to do on a breezy Sunday afternoon. But instead he was waiting his turn at Sinai Temple—along with dozens of other members of Los Angeles' large Persian Jewish community—to undergo genetic testing.
The UCLA student deposited a few drops of saliva in a tube handed to him by a doctor and, in four to six weeks, he'll learn whether he carries gene mutations for four disorders that are especially prevalent among Persian Jews. Three are easy to treat—provided a person knows he or she is afflicted. The fourth is incurable.
The screening program, conducted by the Cedars-Sinai Medical Genetics Institute, is a unique attempt to make broad-scale genetic testing more efficient by targeting ethnicity, a concept called ethnogenetics. Organizers hope to test at least 10,000 of the 30,000 Persian Jews in Southern California.
Tue, 18 Aug 2009
Don't hate those people who are perky and efficient after only a few hours of sleep. They can't help it. New research suggests that a genetic mutation may explain why some people sleep less.
Researchers don't know exactly why some people do fine with as little as 4 hours of sleep a night, while others need 12. "We've believed for a long time that there's a genetic basis," says Paul Shaw, a neurobiologist at Washington University in St. Louis, Missouri. But scientists have only recently begun to ferret out which genes are responsible.
... [Researchers] say they have found the first genetic mutation in humans that appears to affect sleep duration rather than sleep timing. The mutation lies in DEC2, a gene that codes for a protein that helps turn off expression of other genes, including some that control circadian rhythm, the internal clock that regulates a person's sleep-wake cycle.
Tue, 18 Aug 2009
A newly discovered genetic marker helps identify which patients will respond well to hepatitis C treatments and which are likely to fail, scientists at Duke University reported Monday.
Armed with the information, doctors and patients could have a clearer road map as they launch treatment—an often debilitating yearlong regimen of weekly shots and daily pills that cures only about half the time.
"The therapy is unpleasant, to be sure, and that is precisely why both the clinician and patient would want the information up front," said David Goldstein, director of the Center for Human Genome Variation in Duke's Institute for Genome Sciences & Policy, and the senior author of the study. The findings are published in the journal Nature.
Wed, 12 Aug 2009
A Stanford engineer has invented a new technology for decoding DNA and used it to decode his own genome for less than $50,000. The engineer, Stephen R. Quake, says the low cost "will democratize access to the fruits of the genome revolution" by enabling many labs and hospitals to decode whole human genomes.
Until now only companies or genome sequencing centers, equipped with large staffs and hundreds of machines, have been able to decipher the three billion units in a human genome.
Dr. Quake's machine, the Heliscope Single Molecule Sequencer, can decode or sequence a human genome in four weeks with a staff of three people. The machine is made by a company he founded, Helicos Biosciences, and costs "about $1 million, depending on how hard you bargain," he said.
Tue, 11 Aug 2009
Scientists have shown just how mind-bogglingly complex are the genetics underpinning the development of cancer. For the second time a team from Washington University has decoded the complete DNA of a patient with a form of leukaemia.
But the suite of key genetic mutations they found were completely different from those uncovered following analysis of their first patient last year. The study appears in the New England Journal of Medicine.
The latest study does reveal some potentially significant findings. One of the new mutations found in the second patient was also found in samples taken from 15 other patients with the same disease, acute myeloid leukaemia (AML).
Wed, 5 Aug 2009
Scientists have prevented epilepsy caused by a faulty gene from being passed down the generations in mice. The key gene, Atp1a3, regulates levels of chemicals such as sodium and potassium in brain cells.
It has long been suspected that an imbalance of these chemicals may cause some cases of epilepsy. The University of Leeds study, which appears in Proceedings of the National Academy of Sciences, raises hopes of new treatments for the condition.
Lead researcher Dr. Steve Clapcote said: "An imbalance of sodium and potassium levels has long been suspected to lead to epileptic seizures, but our study is the first to show beyond any doubt that a defect in this gene is responsible."
Mon, 3 Aug 2009
Your memories of high school biology class may be a bit hazy nowadays, but there are probably a few things you haven't forgotten. Like the fact that you are a composite of your parents--your mother and father each provided you with half your genes, and each parent's contribution was equal.
... But it turns out that genes from Mom and Dad do not always exert the same level of influence on the developing fetus. Sometimes it matters which parent you inherit a gene from--the genes in these cases, called imprinted genes because they carry an extra molecule like a stamp, add a whole new level of complexity to Mendelian inheritance.
These molecular imprints silence genes; certain imprinted genes are silenced by the mother, whereas others are silenced by the father, and the result is the delicate balance of gene activation that usually produces a healthy baby.
Mon, 20 Jul 2009
Let's say your father has Alzheimer's disease. The withering of his memory is agonizing, and the toll on you grows worse the more he declines.
Your doctor points out that a particular variant of a gene called apolipoprotein E is associated with the likelihood of developing the debilitating disease. A test is available to see if you have it.
Should you have the test? Until now, the advice of the medical community has been to decline. ... The potential downside of wigging out over a bad test result outweighs any possible benefits, doctors have counseled, especially because there's no effective treatment for Alzheimer's.
Fri, 17 Jul 2009
We're all familiar with the stereotype of the tortured artist. Salvador Dali's various disorders and Sylvia Plath's depression spring to mind. Now new research seems to show why: a genetic mutation linked to psychosis and schizophrenia also influences creativity.
The finding could help to explain why mutations that increase a person's risk of developing mental illnesses such as schizophrenia and bipolar syndrome have been preserved, even preferred, during human evolution, says Szabolcs Keri, a researcher at Semmelweis University in Budapest, Hungary, who carried out the study.
Keri examined a gene involved in brain development called neuregulin 1, which previous studies have linked to a slightly increased risk of schizophrenia. Moreover, a single DNA letter mutation that affects how much of the neuregulin 1 protein is made in the brain has been linked to psychosis, poor memory and sensitivity to criticism.
Wed, 15 Jul 2009
... It was a few years ago that [Carlo] Croce began to sniff out one of the most surprising and most promising discoveries in cancer research.
The discovery placed him and his collaborators at the leading edge of a now-booming field that promises improved techniques for diagnosing disease and, they hope, more effective new treatments.
Indeed, Croce's latest work is part of a whole new way of looking at genes and how life regulates itself. Which makes all the more remarkable the fact that his insight came only after he and his co-workers had raced at top speed into a dead end.
Thu, 9 Jul 2009
Dr. Francis S. Collins, the geneticist who discovered the causes of half a dozen diseases, oversaw the government's efforts to map the human genome and wrote a now-famous book presenting scientific evidence for a belief in God, will be nominated to head the National Institutes of Health, the White House confirmed Wednesday. "My administration is committed to promoting scientific integrity and pioneering scientific research, and I am confident that Dr. Francis Collins will lead the NIH to achieve these goals," President Obama said in a written statement.
... The appointment, widely hailed and expected to be readily confirmed, would make Collins one of the most powerful and influential scientists in the country, if not the world, overseeing 27 institutes and an annual budget of nearly $30 billion for biological and medical research.
Tue, 23 Jun 2009
There is a simplicity and all-inclusiveness to the number three—the triangle, the Holy Trinity, three peas in a pod. So it's perhaps not surprising that the Family of Man is divided that way, too.
All of Earth's people, according to a new analysis of the genomes of 53 populations, fall into just three genetic groups. They are the products of the first and most important journey our species made—the walk out of Africa about 70,000 years ago by a small fraction of ancestral Homo sapiens.
One group is the African. It contains the descendants of the original humans who emerged in East Africa about 200,000 years ago. The second is the Eurasian, encompassing the natives of Europe, the Middle East and Southwest Asia (east to about Pakistan). The third is the East Asian, the inhabitants of Asia, Japan and Southeast Asia, and—thanks to the Bering Land Bridge and island-hopping in the South Pacific—of the Americas and Oceania as well.
Wed, 17 Jun 2009
One of the most celebrated findings in modern psychiatry—that a single gene helps determine one's risk of depression in response to a divorce, a lost job or another serious reversal—has not held up to scientific scrutiny, researchers reported Tuesday.
The original finding, published in 2003, created a sensation among scientists and the public because it offered the first specific, plausible explanation of why some people bounce back after a stressful life event while others plunge into lasting despair.
The new report, by several of the most prominent researchers in the field, does not imply that interactions between genes and life experience are trivial; they are almost certainly fundamental, experts agree. But it does suggest that nailing down those factors in a precise way is far more difficult than scientists believed even a few years ago, and that the original finding could have been due to chance.
Wed, 3 Jun 2009
Biologists long thought they understood how genetic mutations cause disease. But recent work has revealed an important twist in the tale and uncovered surprising—even counterintuitive—ways that alterations in DNA can make people sick.
The classic view assumed that what are termed "silent" mutations were inconsequential to health, because such changes in DNA would not alter the composition of the proteins encoded by genes. Proteins function in virtually every process carried out by cells, from catalyzing biochemical reactions to recognizing foreign invaders. Hence, the thinking went, if a protein's makeup ends up being correct, any small glitches in the process leading to its construction could not do a body harm.
... Now investigators are beginning to tease out the effects that silent mutations can have on human health and disease. And findings are suggesting intriguing new avenues for improving the design of genes meant to be used as therapies and for genetic engineering.
Thu, 28 May 2009
Scientists have finished sequencing the mouse genome after a 10-year effort. The humble mouse is the experimental workhorse in laboratories worldwide, so this high-quality genome sequence will aid in the fight against human disease. The search for novel treatments could benefit from a greater understanding of the mouse genetic code, which is about 75% similar to our own. An international team of researchers have published details of the work in the open-access journal PLoS Biology.
The sequence comprises the full complement of genetic material in the nucleus of a cell. It is effectively the genetic "instruction booklet" for a living animal.
Thu, 28 May 2009
NEW YORK (Associated Press)—Scientists have shown that transgenic monkeys can pass a newly acquired gene along to their offspring, a "milestone" for creating animals with versions of human diseases for medical research.
While researchers have long created transgenic mice and other animals by giving them extra genetic material, monkeys offer a promising avenue for medical studies because of their similarity to humans.
Researchers have added genes to rhesus macaques before, but the new work with marmosets is the first to document that monkeys can pass an inserted gene along to future generations. That's important because it opens the door to creating colonies of such "transgenic" monkeys by breeding, which would be far simpler than the cumbersome process of making each animal from scratch by inserting genes into embryos.
Mon, 18 May 2009
A UK-led team located two genes on chromosomes six and nine that appear to strongly influence the age at which menstruation starts.
The Nature Genetics study also provides a clue for why girls who are shorter and fatter tend to get their periods months earlier than classmates. The genes sit right next to DNA controlling height and weight.
A second paper, published in the same journal, also concludes that one of the two genes highlighted by the first study plays a key role in the timing of puberty in both girls and boys.
Mon, 18 May 2009
Breathing in polluted air may wreak havoc on our DNA, reprogramming genes in as few as three days and causing increased rates of cancer and other diseases. So says a new study that tracked DNA damage in 63 steel-foundry workers in Brescia, Italy, who, under their normal factory conditions, were exposed to particulate matter.
The same damage may occur in city dwellers exposed to normal air, the researchers say. Particulate matter includes suspended, tiny bits of dust, metal, or soot in the air, which can lodge deep in the lungs. Exposure to the substance has been linked to respiratory diseases, lung cancer, and heart problems.
Fri, 15 May 2009
When Genae Girard received a diagnosis of breast cancer in 2006, she knew she would be facing medical challenges and high expenses. But she did not expect to run into patent problems.
Ms. Girard took a genetic test to see if her genes also put her at increased risk for ovarian cancer, which might require the removal of her ovaries. The test came back positive, so she wanted a second opinion from another test. But there can be no second opinion. A decision by the government more than 10 years ago allowed a single company, Myriad Genetics, to own the patent on two genes that are closely associated with increased risk for breast cancer and ovarian cancer, and on the testing that measures that risk.
On Tuesday, Ms. Girard, 39, who lives in the Austin, Tex., area, filed a lawsuit against Myriad and the Patent Office, challenging the decision to grant a patent on a gene to Myriad and companies like it. She was joined by four other cancer patients, by professional organizations of pathologists with more than 100,000 members and by several individual pathologists and genetic researchers.
Wed, 13 May 2009
WASHINGTON (Associated Press)—The most detailed look yet at the genetics of Mexicans is showing significant diversity, a finding that could help point the way to customized drugs and identification of people prone to certain diseases.
Researchers led by Dr. Gerardo Jimenez-Sanchez studied the genes of 300 mestizos—people of mixed Indian and European background—from six states in Mexico, and one Indian population.
They found significant differences between the mestizos and such groups as Europeans, Africans and Asians, the researchers reported in Tuesday's edition of Proceedings of the National Academy of Science.
Tue, 12 May 2009
CAMBRIDGE—In her humble first-floor apartment, Katherine Aull is searching for a killer that has stalked her family for generations. But this is no manhunt. Aull is scouring her own genes in pursuit of a potentially lethal mutation that she may have inherited from her parents—and she has transformed her bedroom closet into a makeshift scientific laboratory to conduct the hunt.
The 23-year-old MIT graduate uses tools that fit neatly next to her shoe rack. There is a vintage thermal cycler she uses to alternately heat and cool snippets of DNA, a high-voltage power supply scored on eBay, and chemicals stored in the freezer in a box that had once held vegan "bacon" strips.
Aull is on a quirky journey of self-discovery for the genetics age, seeking the footprint of a disease that can be fatal but is easily treated if identified. But her quest also raises a broader question: If hobbyists working on computers in their garages can create companies such as Apple, could genetics follow suit?
Fri, 1 May 2009
The history of Africa, the cradle of humanity, is written in its genes. And now we have our best-ever view of African genetic diversity, with the publication of a huge study of the genomes of people from across the continent.
For the past 10 years, an international team led by Sarah Tishkoff of the University of Pennsylvania in Philadelphia has toured the African continent, collecting blood samples from thousands of individuals. The results confirm Africa as the centre of human genetic diversity and, together with linguistic data, reveal a rich pattern of human migrations within the continent.
"Now we have a spectacular insight into the history of African populations," says Muntaser Ibrahim of the University of Khartoum in Sudan, a member of the team.
Wed, 22 Apr 2009
Gregory Cochran has always been drawn to puzzles. This one had been gnawing at him for several years: Why are European Jews prone to so many deadly genetic diseases? Tay-Sachs disease. Canavan disease. More than a dozen more. It offended Cochran's sense of logic. Natural selection, the self-taught genetics buff knew, should flush dangerous DNA from the gene pool. Perhaps the mutations causing these diseases had some other, beneficial purpose. But what? At 3:17 one morning, after a long night searching a database of scientific journals from his disheveled home office in Albuquerque, Cochran fired off an e-mail to his collaborator Henry Harpending .... "I've figured it out, I think," Cochran typed. "Pardon my crazed excitement." The "faulty" genes, Cochran concluded, make Jews smarter.
Wed, 22 Apr 2009
Scientists have identified a genetic reason why boys are significantly more likely than girls to suffer learning difficulties. A set of nine genes that cause mental retardation when defective has been identified in the biggest genetic investigation of its kind yet conducted. The rare genetic mutations all lie on the X chromosome leaving males far more likely to be hit.
Women have two copies of the X chromosome and if one carries a mutation in an important gene the other can sometimes provide a back-up. Men, however, have one X chromosome and one Y chromosome, so a mutation in an important X-linked gene will generally have serious adverse effects.
Tue, 21 Apr 2009
Six years ago Katherine S. Pollard jumped at an opportunity to join the international team that was identifying the sequence of DNA bases, or "letters," in the genome of the common chimpanzee (Pan troglodytes). As a biostatistician with a long-standing interest in human origins, she was eager to line up the human DNA sequence next to that of our closest living relative and take stock.
A humbling truth emerged: our DNA blueprints are nearly 99 percent identical to theirs. That is, of the three billion letters that make up the human genome, only 15 million of them--less than 1 percent--have changed in the six million years or so since the human and chimp lineages diverged. Evolutionary theory holds that the vast majority of these changes had little or no effect on our biology. But somewhere among those roughly 15 million bases lay the differences that made us human. Pollard was determined to find them. Since then, she and others have made tantalizing progress in identifying a number of DNA sequences that set us apart from chimps.
Thu, 16 Apr 2009
The era of personal genomic medicine may have to wait. The genetic analysis of common disease is turning out to be a lot more complex than expected. Since the human genome was decoded in 2003, researchers have been developing a powerful method for comparing the genomes of patients and healthy people, with the hope of pinpointing the DNA changes responsible for common diseases.
This method, called a genomewide association study, has proved technically successful despite many skeptics' initial doubts. But it has been disappointing in that the kind of genetic variation it detects has turned out to explain surprisingly little of the genetic links to most diseases. A set of commentaries in this week's issue of The New England Journal of Medicine appears to be the first public attempt by scientists to make sense of this puzzling result.
Wed, 8 Apr 2009
A new DNA test for the virus that causes cervical cancer does so much better than current methods that some gynecologists hope it will eventually replace the Pap smear in wealthy countries and cruder tests in poor ones.
Not only could the new test for human papillomavirus, or HPV, save lives; scientists say that women over 30 could drop annual Pap smears and instead have the DNA test just once every 3, 5 or even 10 years, depending on which expert is asked. Their optimism is based on an eight-year study of 130,000 women in India financed by the Bill and Melinda Gates Foundation and published last week in The New England Journal of Medicine. It is the first to show that a single screening with the DNA test beats all other methods at preventing advanced cancer and death.
Tue, 31 Mar 2009
The human genome is an indisputably stunning piece of work: 25,000 or so genes containing all of the essential instructions for building a being. Still, it's only a guide. Alone, the genome cannot construct a person. The "book of life" requires a vocabulary of attendant molecules, compounds and chemicals--a biochemical language, so to speak--to help genes write the individual story of you.
Altogether, this phenomenon is called epigenetics. Its study represents one of the cutting edges of bioscience, offering the possibility of not just curing diseases like cancer and diabetes, but preventing them altogether.
"The human epigenome is the next frontier of genomic research," said Bing Ren, an associate professor of cellular and molecular medicine at the University of California San Diego, which recently received a five-year, $16.6 million grant from the federal National Institutes of Health (NIH) to establish The San Diego Epigenome Center at the Ludwig Institute for Cancer Research on campus.
Mon, 16 Mar 2009
23andMe, the gene-testing company backed by Google Inc., wants to collect DNA from the spit of 10,000 people with Parkinson's disease to hunt for common genes that may cause the illness or predict patients' response to drugs.
To entice patients to participate, the Mountain View, California-based company will offer to test them for $25, a fraction of the normal $399 fee. The quest is personal for Ann Wojcicki, who helped start 23andMe in 2006. Her husband, Google co-founder Sergey Brin, has a gene variant that increases his risk of developing the neurological condition, which afflicts his mother.
One million North Americans and more than 4 million people worldwide have Parkinson's, which causes people to tremble, shake and lose control of their body's movements. The condition comes in different forms, and its causes are poorly understood, with a handful of genes known to increase the risk. 23andMe hopes to uncover others.
Wed, 11 Mar 2009
When Jo Symons was found to have cancer, there was an extra complication: doctors could not tell what type of cancer she had. Tumors were found in her neck, chest and lymph nodes. But those tumors had spread there from someplace else, and her doctors could not determine whether the original site was the breast, the colon, the ovary or some other organ. Without that knowledge, they could not offer optimal treatment.
Such mystery tumors are estimated to account for 2 percent to 5 percent of all cancer, or at least 30,000 new cases a year in the United States, making them more common than brain, liver or stomach cancers. For patients, such a diagnosis can amount to a double agony--not only do they have cancer, but doctors cannot treat it properly.
But now 21st-century medicine may help. New genetic tests may pinpoint the origin of the mystery tumors. The tests, which cost more than $3,000 each, still need to prove their worth better, experts say, though some of them are hopeful.
Wed, 25 Feb 2009
One of the enduring mysteries of biology is that a variety of specialized cells collaborate in building a body, yet all have an identical genome. Somehow each of the 200 different kinds of cells in the human body--in the brain, liver, bone, heart and many other structures--must be reading off a different set of the hereditary instructions written into the DNA.
The system is something like a play in which all the actors have the same script but are assigned different parts and blocked from even seeing anyone else's lines. The fertilized egg possesses the first copy of the script; as it divides repeatedly into the 10 trillion cells of the human body, the cells assign themselves to the different roles they will play throughout an individual's lifetime. How does this assignment process work? The answer, researchers are finding, is that a second layer of information is embedded in the special proteins that package the DNA of the genome. This second layer, known as the epigenome, controls access to the genes, allowing each cell type to activate its own special genes but blocking off most of the rest.
Fri, 13 Feb 2009
The first draft of the genome of a 38,000 year-old Neanderthal is complete, scientists announced Thursday.
Early glimpses of the genome, which was sequenced by Svante Paeaebo, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues, have already cast new light on the ancient human species that went extinct more than 25,000 years ago.
"This will be the first time the entire genome of an extinct organism has been sequenced," Paeaebo told the annual meeting of the American Association for the Advancement of Science, in Chicago. Now study of the more complete genome will allow scientists to examine Neanderthals' relationship with modern humans as never before. A preliminary analysis of the sequence suggests that Neanderthals contributed few, if any, genes to humans via inbreeding.
Tue, 27 Jan 2009
It's no surprise that there's a gene in congeniality. After all, how well you make friends obviously depends to some degree on heritable personality traits such as whether you are gregarious or shy.
But in a paper published in the online version of the Proceedings of the National Academy of Sciences yesterday, researchers at the University of California San Diego and Harvard Medical School say heredity also strongly influences whether your friends know each other, and it helps determine your standing in social networks. "Basically, we think there's a gene that causes some people to be more likely to introduce one friend to other friends, with the result being that some people create denser clusters of social networks around them than others do," said Dr. Nicholas Christakis, a professor of medical sociology at Harvard.
Mon, 12 Jan 2009
... The Personal Genome Project is an initiative in basic research, not personal discovery. Yet the technological advance making it possible -- the plunging cost of genome sequencing -- will soon give people an unprecedented opportunity to contemplate their own biological and even psychological makeups.
We have entered the era of consumer genetics. At one end of the price range you can get a complete sequence and analysis of your genome from Knome (often pronounced "know me") for $99,500. At the other you can get a sample of traits, disease risks and ancestry data from 23andMe for $399.
... Like the early days of the Internet, the dawn of personal genomics promises benefits and pitfalls that no one can foresee. It could usher in an era of personalized medicine, in which drug regimens are customized for a patient's biochemistry rather than juggled through trial and error, and screening and prevention measures are aimed at those who are most at risk. It opens up a niche for bottom-feeding companies to terrify hypochondriacs by turning dubious probabilities into Genes of Doom.
Thu, 4 Dec 2008
BOULDER, Colo.–When Donna Campiglia learned recently that a genetic test might be able to determine which sports suit the talents of her 2 1/2-year-old son, Noah, she instantly said, Where can I get it and how much does it cost?
... In health-conscious, sports-oriented Boulder, Atlas Sports Genetics is playing into the obsessions of parents by offering a $149 test that aims to predict a child's natural athletic strengths. The process is simple. Swab inside the child's cheek and along the gums to collect DNA and return it to a lab for analysis of ACTN3, one gene among more than 20,000 in the human genome.
... In this era of genetic testing, DNA is being analyzed to determine predispositions to disease, but experts raise serious questions about marketing it as a first step in finding a child's sports niche ...
Fri, 14 Nov 2008
Two large-scale genetic analyses have turned up a trio of new sites associated with autism, including a large-effect allele that seems to reduce the risk of developing the debilitating brain disorder, researchers reported Wednesday at the American Society of Human Genetics meeting in Philadelphia.
Last year, the Autism Genome Project Consortium performed the largest genome-wide linkage scan to date with around 10,000 SNPs in 1,181 families with at least two affected individuals. The group flagged a handful of genomic regions harboring autism susceptibility genes, although none of the linkage results were statistically significant.
Now, a team led by Dan Arking, a geneticist at Johns Hopkins University, has ramped up the SNP count to include around 500,000 markers in 802 affected pairs of siblings. They then eliminated all the error-prone or uninformative SNPs to amass a collection of 180,000 high-quality markers for their analysis. "It's the cleanest best set of markers you can imagine," Arking said at a press conference.
Tue, 11 Nov 2008
Over the summer, Sonja Prohaska decided to try an experiment. She would spend a day without ever saying the word "gene." Dr. Prohaska is a bioinformatician at the University of Leipzig in Germany. In other words, she spends most of her time gathering, organizing and analyzing information about genes. "It was like having someone tie your hand behind your back," she said.
But Dr. Prohaska decided this awkward experiment was worth the trouble, because new large-scale studies of DNA are causing her and many of her colleagues to rethink the very nature of genes. They no longer conceive of a typical gene as a single chunk of DNA encoding a single protein. "It cannot work that way," Dr. Prohaska said. There are simply too many exceptions to the conventional rules for genes.
It turns out, for example, that several different proteins may be produced from a single stretch of DNA. Most of the molecules produced from DNA may not even be proteins, but another chemical known as RNA. The familiar double helix of DNA no longer has a monopoly on heredity.
Tue, 11 Nov 2008
Someday soon, a company will offer to decode your genome for as little as $1,000. To make sense of your unique collection of A's, Cs, Ts and Gs, you may turn to a genetic counselor—DNA guides who have been advising patients since the early 1970s. The profession routinely appears on lists of hot jobs for the 21st century. During the National Society of Genetic Counselors annual meeting last month in Los Angeles, President Angela Trepanier took a break to discuss the future of personalized medicine with the Los Angeles Times.
Fri, 7 Nov 2008
For the first time, a complete cancer genome, and incidentally a complete female genome, has been decoded, scientists report online Nov. 5 in Nature. In a study made possible by faster, cheaper and more sensitive methods for sequencing DNA, the researchers pinpoint eight new genes that may cause a cell to turn cancerous. "Since cancer is a disease of the genome, this newfound ability to determine the complete DNA sequence of a cancer cell is enormously powerful," comments Francis Collins, a geneticist and former director of the National Human Genome Research Institute in Bethesda, Md., a group that raced to sequence the first entire human genome.
"We need to know the genetic rules of cancer," says coauthor Timothy Ley of Washington University in St. Louis. Ley and colleagues read each of the 3 billion building blocks of DNA from tumor cells in a woman with acute myeloid leukemia, or AML, a highly malignant form of blood and bone marrow cancer.
Tue, 4 Nov 2008
Here's the dilemma. At a fundamental level, we age because our cells stop dividing and multiplying. So why shouldn't medical science try to extend our lifespans and improve our health in old age by making sure our cells keep proliferating?
The answer is cancer. Any measures we take to keep tissues growing might raise the odds of cancer, which is characterized by cells that never stop dividing.
Patricia Opresko lives at the intersection of this quandary. A researcher at the University of Pittsburgh's Graduate School of Public Health, Dr. Opresko studies the basic mechanisms of why cells age, partly by specializing in a rare premature aging malady known as Werner syndrome.
Fri, 31 Oct 2008
Sporting champions are more likely to have children who go on to succeed in their own right because mental toughness is inherited, new research suggests.
... In a study published Wednesday, scientists studied 219 sets of twins to work out the influence of genetics and environment on four character traits associated with mental toughness. They were control over life, commitment, confidence and the ability to face new challenges.
Author Dr Tony Vernon at the University of Western Ontario in London, Canada, concluded that genetics played a more important role—52 per cent—than environmental factors—48 per cent.
Mon, 20 Oct 2008
George Church wants to put his personal genetic blueprint online for all to see—the sequence of chemical bases that make him who he is, a lanky scientist of Scottish ancestry who has dyslexia, narcolepsy and motion sickness. And he wants 99,999 other people to follow suit.
The Harvard genetics professor's Personal Genome Project is an attempt to build the only public genomic database that connects genes with diseases.
With it, he believes, scientists could correlate more easily many millions of genetic variants with medical and other traits, from asthma to acne, eye color to perfect pitch.
Wed, 15 Oct 2008
The US National Institutes of Health (NIH) handed out the first payments in a multi-million-dollar project to explore epigenomics last month. But some researchers are voicing concerns about the scientific and economic justification for this latest 'big biology' venture.
Epigenetics, described as "inheritance, but not as we know it," is now a blisteringly hot field. It is concerned with changes in gene expression that are typically inherited, but not caused by changes in gene sequence.
In theory, epigenetic studies can help explain how the millions of cells in the human body can carry identical DNA but form completely different cell types, and perhaps why certain cells are susceptible to disease. The NIH's epigenomics initiative is a plan for such studies on a grand scale...
Thu, 9 Oct 2008
The University of Minnesota has concluded that falsified data were used in a 2001 article published by one of its researchers on adult stem cells. The school is asking that the article be retracted.
The conclusion follows an 18-month investigation into research published by stem-cell expert Dr. Catherine Verfaillie. The investigation clears Verfaillie of misconduct but points to a former graduate student, Dr. Morayma Reyes, who is now an assistant professor at the University of Washington.
The university blames Verfaillie for "inadequate training and oversight," and says it has asked for a retraction of the published article, which appeared in the journal Blood. Reyes said it was an honest error and there was no intent to deceive.
Fri, 5 Sep 2008
Scientists have mapped the cascade of genetic changes that turn normal cells in the brain and pancreas into two of the most lethal cancers. The result points to a new approach for fighting tumors and maybe even catching them sooner.
Genes blamed for one person's brain tumor were different from the culprits for the next patient, making the puzzle of cancer genetics even more complicated. But Friday's research also found that clusters of seemingly disparate genes all work along the same pathways.
So instead of today's hunt for drugs that target a single gene, the idea is to target entire pathways that most patients share. Think of delivering the mail to a single box at the end of the cul-de-sac instead of at every doorstep. The three studies, published in the journals Science and Nature, mark a milestone in cancer genetics.
Tue, 5 Aug 2008
Genghis Khan spread his seed so liberally that nearly a tenth of men now living in the former Mongolian empire trace their ancestry back to the 13th-century warrior. However, a new analysis suggests that most socially dominant males contribute no more to the genetic pool than do their supposed inferiors.
"An individual really doesn't have the opportunity to set up things so their genetic information pervades the gene pool a long time in the future," says mathematician Joseph Watkins, of the University of Arizona in Tucson. "It could happen because life is chaotic."
Theories on how genes flow through populations of organisms generally support this idea, which has been dubbed neutrality. But some anthropologists argue that cultural dominance can seal a man's legacy. For instance, a rich and powerful father can ensure the status of his sons and grandsons.
Thu, 31 Jul 2008
Two groups of researchers hunting for schizophrenia genes on a larger scale than ever before have found new genetic variants that point toward a different understanding of the disease.
The variants discovered by the two groups, one led by Dr. Kari Stefansson of Decode Genetics in Iceland and the other by Dr. Pamela Sklar of Massachusetts General Hospital, are rare. They substantially increase the risk of schizophrenia but account for a tiny fraction of the total number of cases.
This finding, coupled with the general lack of success so far in finding common variants for schizophrenia, raises the possibility that the genetic component of the disease is due to a large number of variants, each of which is very rare, rather than to a handful of common variants.
Thu, 31 Jul 2008
For as long as people have vied for sporting glory, they have also sought shortcuts to the champion's rostrum. Often, those shortcuts have relied on the assistance of doctors. After all, most doping involves little more than applying existing therapies to healthy bodies.
These days, however, the competition is so intense that existing therapies are not enough. Now, athletes in search of the physiological enhancement they need to take them a stride ahead of their opponents are scanning medicine's future, as well as its present. In particular, they are interested in a field known as gene therapy.
Gene therapy works by inserting extra copies of particular genes into the body. These extra copies, known as "transgenes," may cover for a broken gene or regulate gene activity. Though gene therapy has yet to yield a reliable medical treatment, more than 1,300 clinical trials are now under way. As that number suggests, the field is reckoned to be full of promise.
Thu, 24 Jul 2008
McKusick was a pioneer in linking diseases to specific genes and began the first database of gene functions, a repository that now includes more than 18,000 human genes.
The two-week course in genetics taught by McKusick and his colleagues every summer in Bar Harbor, Maine, became the best-known and most respected course in the subject, bringing in more than 4,000 students, doctors and researchers from all over the country and introducing them to an entirely new way of addressing illnesses.
Fri, 18 Jul 2008
Some favor using genetic markers to sort humans into groups based on ancestral origin—groups that may show meaningful health differences. Others argue that genetic variations across the human species are too gradual to support such divisions and that any categorisation based on genetic differences is arbitrary.
These issues have been discussed in depth by a multidisciplinary group—ranging from geneticists and psychologists to historians and philosophers—led by Sandra Soo-Jin Lee of Stanford University, California. Now the group has released a set of 10 guiding principles for the scientific community, published as an open letter in this week's Genome Biology.
Wed, 9 Jul 2008
If this ambitious project is ever realized, the throngs of African pilgrims who traverse one of the longest bridges in the world on a journey to Mecca would pass hundreds of feet above the probable route of the most memorable journey in human history. Fifty or sixty thousand years ago a small band of Africans ... crossed the strait in tiny boats, never to return.
... In the past 20 years population geneticists have begun to fill in gaps in the paleoanthropological record by fashioning a genetic bread-crumb trail of the earliest migrations by modern humans.
Mon, 7 Jul 2008
The puffy appearance was a known sign that genes were being activated in those regions to give rise to their encoded proteins, so those sites of activity became known as the heat shock loci.
The effect was reproducible but initially considered to be unique to the fruit fly. It took another 15 years before the proteins generated when these chromosome puffs appear were detected in mammals and other forms of life. In what is certainly among the most absorbing stories in contemporary biology, heat shock proteins (HSPs) have since been recognized as occupying a central role in all life ...
Fri, 27 Jun 2008
... Researchers from Cambridge University say that women whose test result shows they are at high risk could be called for screening at a much younger age, while those at low risk could defer mammograms until they are 55 or older.
The test could be a simple mouth swab, said Dr Paul Pharoah from Cambridge University's department of oncology. ... In a paper published [yesterday] in the New England Journal of Medicine, Pharoah and colleagues say that there are seven genetic variants ... which have been discovered to increase a woman's risk of breast cancer, particularly if she has certain combinations of them.
Thu, 26 Jun 2008
The California Department of Public Health sent "cease and desist" letters to 13 genetic testing companies two weeks ago, telling them they could not solicit business from state residents. The companies include the early leaders in the field—23andMe, Navigenics and deCode Genetics—which are trying to carve out a new business of offering personal genetic information for use in health and lifestyle planning...
Yet the move to regulate the tests is raising many issues. What are the standards for proving a genetic test is valid? Must a doctor always be involved in ordering such tests to protect patients, or is that an attempt by doctors to protect their turf?
Every weekday, Sigma Xi, the Scientific Research Society, selects a set of significant and interesting science-related news articles from the mainstream media. The news stories featured here are selected from Sigma Xi's daily Science in the News e-mail. http://www.mediaresource.org/news.instruct.shtml
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